Development and validation of an HPLC-DAD-FL method for the determination of food supplements adulteration with undeclared phosphodiesterase type-5 inhibitor drugs Conference Paper uri icon


  • The consumption of food supplements has been increasing in developed countries. However, regulations and guidelines for this type of products reveal several gaps, and do not guarantee an efficient quality control, allowing for the possibility of intentional adulteration. Supplements used for improvement of male sexual performance are among the most popular food supplements. One of the major concerns in these products is the possible adulteration with synthetic drugs used for the treatment of erectile dysfunction, namely phosphodiesterase type-5 (PDE-5) inhibitor drugs, such as sildenafil, vardenafil and tadalafil. The side effects of these compounds and possible interactions with other drugs are well documented, thus its illegal addition to food supplements could pose a serious risk for consumers with known health constraints [1]. In the last years, the presence of this type of drugs have been detected by FDA in the US and reported in food supplements commercialized in Asia and the EU. Recently, Portuguese legal authorities reported the apprehension of some food supplements due to the presence of illegal PDE-5 inhibitor drugs. In this work, an high performance liquid chromatography (HPLC) based method was developed and validated for the detection of four PDE-5 inhibitors, namely sildenafil, vardenafil, tadalafil and yohimbine, in three sexual performance enhancement supplements. The analyses were performed by HPLC-DAD-FL in a JASCO chromatograph following the conditions of a previously published method [2]. A YMC-Triart C18 analytical column (3 μm, 250 × 4.6 mm) was used, together with (A) 50 mM Ammonium acetate; (B) acetonitrile/ methanol (50:50) as eluents. A simple liquid-liquid extraction with sonication using acetonitrile/methanol (50:50) was used in all samples. To validate the proposed methodology, the limits of detection (LOD) and quantification (LOQ), linearity range, intra- and inter-day precision and accuracy of the method were determined, showing high reproducibility scores and adequate recoveries for the tested compounds. One of the analyzed supplements showed the illegal addition of sildenafil.
  • financial support from FCT and EU (FEDER funds through COMPETE) through projects PEst-C/EQB/LA0006/2013 and EXPL/DTP-SAP/1438/2013

publication date

  • January 1, 2015